PROJECT SUMMARY/ABSTRACT 7-9% of children are affected by language disorders such as Developmental Language Disorder (DLD). DLD ? the most common type of specific language impairment ? results in difficulties with producing and understanding language despite otherwise normal development. Even with increased attention on early identification methods, as many as 70% of school-age children with DLD are not identified or receiving services to ensure they succeed (Adlof et al., 2017; Tomblin, et al., 1997). While DLD is often under-identified in mainstream American populations, both over-identification and under-identification are common in children who speak non-mainstream dialects, such as African American English (AAE) (Morgan et al., 2015; Seymour, Bland-Stewart, & Green, 1998). This leads to a serious problem in potentially misallocated treatment resources. Despite increased efforts to improve speech and language assessments for children who speak AAE, many speech-language pathologists working in schools report that they are not confident in determining whether children who speak non-mainstream dialects have communication disorders and report underutilizing effective assessment and intervention strategies (Hendricks & Diehm, under review). A new framework ? Disorder within Diversity ? utilizes comparisons between children with and without language disorders who speak the same dialects to improve identification and treatment of language disorders (Garrity & Oetting, 2010; Oetting & MacDonald, 2001; Oetting et al, 2013). To date, this framework has focused on language skills among preschool and kindergarten students, and less is known about language production and comprehension among school-age children with DLD. Research on students with typical language skills indicates that early elementary school is a pivotal time as students demonstrate significant changes in their use of morphosyntactic markers during first and second grades. Further, children who exhibit larger changes in their use of morphosyntax tend to have stronger language and literacy skills (see Washington et al., 2018 for a review). However, these associations have yet to be investigated in school-age children with language disorders. This project bridges two separate research traditions: research on preschool children with language disorders and research on school-age children with typical language skills. We examine morphosyntactic skills using a battery of complementary tasks, including well-established language sampling methods and innovative eyetracking methods. Our novel recruitment procedures and rigorous analytic approach are carefully tailored to address the research questions. The long- term goal of this research is to better understand how children who speak different dialects, including those with and without language disorders, acquire language. This new knowledge has the potential to broaden theories of language disorders to better capture experiences of diverse students and help clinicians make more accurate diagnostic decisions for children from culturally and linguistically diverse backgrounds.